An original reading apparatus including an automatic document feeder (hereinafter “ADF”) for automatically feeding sheets of an original is well known in the art. One example of this original reading apparatus is a copying device including an ADF, an entry sensor that detects the leading edge of an original fed onto a platen, and conveying rollers that perform a preliminary conveying operation (hereinafter “pre-feed”) for conveying the original a prescribed amount when the sensor detects the leading edge of the original. Through this pre-feed, the copying device conveys the original over the platen until the leading edge of the original reaches a read position.
Another original reading apparatus known in the art is an original reader that includes an ADF, a sensor for detecting the leading edge of an original, conveying rollers for executing a pre-feed once the sensor detects the leading edge of an original in order to feed the original to the read position, and reading unit for detecting changes in reflected light so as to recognize when the leading edge of the original has arrived at the read position before beginning an operation to read the original.
In general, the ADF-equipped original reading apparatuses described above begin a pre-feed when an original has been placed onto the platen. Once the pre-feed is completed, the user inputs a read command into the original reading apparatus, and the original reading apparatus begins executing a reading operation and a conveying operation for the original in response to the read command. Since the original reading apparatus automatically conveys the original to the read position when the original is placed on the platen, this method of reading an original can shorten the time required for the device to begin reading the original after the user inputs a read command.